1. Field of the Invention
This invention relates to valves for pneumatic tires and the like. More specifically, it relates to valves usable with off-highway vehicles such as large earth-moving equipment and mining and agricultural equipment. It has special application to large diameter high pressure tires equipped with fast filling and discharging fittings commonly called "super bore" connections.
2. Description of the Prior Art
The prior art abounds with references showing valves for pneumatic tires. These valves are of virtually every description but by far the majority require a spring forcing the valve to the closed position and have valve pin bridges of considerable width supporting the valve pin. In commercial use, valves of the art are of relatively small diameter. These factors, the presence of the springs, substantial pin bridges and the small diameter, have underlined the deficiencies of prior devices for use in tires on heavy equipment. Flow rates during filling and discharge have been slow because of the destruction of these structures. Further, in connection with certain prior valves of the core housing type, fast deflation has been achieved by removal of the entire core housing. There has been a hazard in deflating such tires in that the core and/or core housing will literally be "shot" out of the valve stem, pressured by the tire air pressure where pressure is often in excess of 100 lbs. per square inch. Removal of such a core housing has also, of course, required special tools.
Herein the word "tire" is used for simplicity to include tires, bags, tanks and other gas and air containers with which the valve may be used.